(a) Field of the Invention
The present invention relates to an integrated base station and a terminal.
(b) Description of the Related Art
WiFi is a system that provides a wireless connection to a wired LAN environment. WiFi allows a user terminal to use the internet via a wireless access point (AP) installed on an internet connection line. WiFi has grown as an effective way to deal with the increase in mobile traffic, fuelled by the growth of smartphones, due to its simple structure and low communication costs.
Small cells are cells that are run by a base station in a mobile communication system that have a range of 10 to 20 meters, which are installed and operate in homes or buildings. In the analysis of an example of mobile communication users, small cell environments can be regarded as one of the next-generation mobile communication infrastructures capable of minimizing the decline in radio resource spectrum efficiency, caused by wall loss, in view of the fact that 70% of users tend to communicate indoors.
Typical examples of small cells include femtocells and picocells. Small cells are mobile communication systems which are small and low-powered mobile communication base stations that are run in homes. Fixed femtocell backhaul is typically a broadband internet network or a dedicated line, which connects small cells to a core network for mobile communication systems.
WiFi offers advantages like simplicity and low communication costs. However, it does not allow for charging, QoS (Quality-Of-Service) control, and handover because of the lack of per-user session management. On the other hand, small cells allow for per-user session management, handover, etc., but have the drawbacks of complex network structure and high communication costs compared with WiFi.
These two technologies have one major thing in common: support for wireless network offloading to overcome mobile traffic big bang. Therefore, though formerly considered competitors, the two technologies are now viewed as working collaboratively in unison to make best use of their own features and complement each other.
Small cells are usually personal cells because they are “small” compared to a macrocell. That is, unlike a macrocell on which many unspecified users in public areas can camp, a cell owner and people who have a connection with the cell owner, e.g., the cell owner's family, enterprise employees, or in-store customers can camp on a small cell. Accordingly, if the user camps on the small cell, this can be applied as very meaningful information and used for small-cell based services.
Examples of such small cell-based services can encompass a Virtual Memo service. With the Virtual Memo service, the user can write a message to a family member, and the family member can receive the message on his or her mobile phone as his or her presence is detected when he or she returns to a house. Since a message is delivered when the recipient enters the house, rather than when the user leaves the message, Virtual Memo makes messaging realistic, as if writing a message and leaving it on the fridge with a magnet. To provide such a small cell-based service, it is necessary for a base station to detect the user's camping on a small cell.
In the conventional standard technology, only the user terminal detects a camp-on event in the process of the terminal making a cell selection or reselection based on broadcast information. Afterwards, though the base station can be aware of a camp-on event in the process of the terminal's session configuration, not every terminal camping on a cell will detect its camp-on event, in view of the fact that only a terminal that requires session configuration can detect a camp-on event. Particularly, if the terminal switches to another cell after session configuration while being in the idle state since no data is used, the base station cannot detect the terminal's camp-on event without explicit session re-configuration.
A typical way of notifying a base station of a terminal's camp-on event is to send a message about cell selection or reselection wirelessly to the base station. This involves making many modifications to the existing standards, which will take considerable effort and time.
Moreover, a random access procedure is needed to report a message wirelessly to the base station. Thus, the radio resource costs required for random access are expected to rise. Accordingly, there arises a demand for a technique to detect a mobile terminal's camping on a cell that does not involve making many modifications to the existing standards and does not cause a rise in the cost of random access.
The conventional methods for a base station to detect a terminal's camping on a cell in a small-cell environment have the drawbacks of having to make many modifications to the standards and causing a rise in the cost of random access, because they are realized by means of small-cell technology and its related infrastructure.